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W Chantratita

Publications and source records attributed to W Chantratita.

18 recordsLinked to original sources
PubMed2001

Survey of reverse transcriptase from the heterosexual epidemic of human immunodeficiency virus type 1 CRF01_AE in Thailand from 1990 to 2000.

Genetic diversity of the HIV-1 envelope gene has shown a steady increase over time in the Thai and other regional epidemics. A serial survey of subtype CRF01_AE polymerase gene (RT) diversity in Thailand was performed, using 48 novel and 15 reported sequences covering the period 1990--2000. These sequences were gathered from individuals whose sole risk factor for infection was heterosexual contact. By contrast to envelope, diversity was low and, despite a 40% increase early in the epidemic, has remained static since 1996. These results indicate that epidemic HIV-1 may be constrained within defined limits of genetic diversity at least in some genomic regions.

Amino Acid Sequence↗
PubMed2001

Genotypic subtyping of the HIV-1 polymerase gene in 30 naåve patients from Thailand.

To investigate the subtype classification of the circulating virus strains among infected Thai patients with human immunodeficiency virus type 1 (HIV-1). A random population of patients who were HIV-1 antibody positive after two independent screening assays was selected. HIV RNA from plasma samples was reverse-transcribed and amplified with specific primers that annealed to conserve regions of the HIV-1 pol gene. Amplified products were sequenced directly by using an automated sequencer. The sequencing products represent about 1.2 kb of the pol gene from each patient and they were phylogenetically analyzed and compared to the corresponding pol sequences of the published HIV-1 sequences of known genotypes. Genotype E was found in 25 of 30 patients (83.3%), and 5 patients (16.7%) were HIV-1 genotype B. The result confirmed that HIV-1 subtype E is still predominant in Thailand. Genotype B is found frequently, but there have been no examples of genotype A. In concordance with the serotypic assay, which was previously reported using the V3-peptide enzyme immunoassay (V3-PEIA), the genotypic assay of subtype E was high, at 80% and 83.3% in serotyping and genotyping, respectively. These findings of two subtypes with low heterogeneity indicate that Thailand may be a desirable site for evaluating candidate HIV-1 antiretroviral drugs and vaccines. The mixture of subtype E and B' strains also offers the opportunity to study phenotypic differences between the two subtypes.

DNA-Directed RNA Polymerases↗
PubMed2000

Plasma HIV-1 RNA viral load and serum vitamin A and E levels in HIV-1 infected pregnant women.

The aim of this study was to assess the correlation between plasma HIV-1 RNA viral load and serum vitamin A and E concentrations and vitamin E/cholesterol ratio in HIV-1 infected pregnant women not receiving antiretroviral therapy There were no significant correlations between plasma HIV-1 RNA viral load and serum vitamin A and E concentrations and vitamin E/cholesterol ratio. However, the presence of underlying vitamin A deficiency in these pregnant women was common.

Adult↗
PubMed2000

Preliminary report for the application of nucleic acid sequence-based amplification in detection of human cytomegalovirus (HCMV) late pp67 mRNA for diagnosis of HCMV infection.

Human cytomegalovirus (HCMV) late pp67 mRNA expression by nucleic acid sequence-based amplification (NASBA) in patients, clinically diagnosed as possible HCMV, probable HCMV disease, and no disease, was evaluated. The RNAs were isolated from 11 whole-blood samples of 11 patients for the specific amplification of the pp67 mRNA. NASBA results were compared to results from PCR assay and serological assay. The HCMV pp67 mRNA could be found in 3 of 11 patients, whereas, HCMV-DNA PCR was positive in 6 of 11 patients. PCR assay for HCMV-DNA in plasma has proved to correlate with clinical diagnosis of HCMV infection. Only 2 patient samples of NASBA positive results coincided with HCMV-DNA PCR. However, the diagnosis of clinically relevant HCMV infection by NASBA was seen. Anti-CMV IgG titers of 1:1,600 or over 1:1,600 were found in 2 of 3 NASBA positive cases and 5 of 6 HCMV-DNA positive cases, whereas, anti-CMV IgM were all negative. These results showed the correlation of HCMV infection detected by NASBA, PCR assay and anti-CMV IgG of the titers up to 1:1,600. Additionally, a low antibody titer of the HIV patient could be diagnosed by NASBA or PCR. In conclusion, pp67 mRNA NASBA appears to be a promising diagnostic tool in analysis of HCMV infection and/or disease. Its diagnostic value should be defined in the specific group for the follow-up of immunocompromised patients, such as organ transplant recipients in future prospective studies.

Adolescent↗
PubMed2000

Forensic identification by DNA fingerprinting and mitochondrial DNA typing.

Short tandem repeats (STRs), that represent an important source of highly polymorphic markers in human genome, and mitochondrial DNA (mtDNA) typing, that its sequences were conserved within the same maternal lineage, facilitated by use of the polymerase chain reaction (PCR) provide a powerful tool for forensic identification. We report the analysis of 9 STR loci and mtDNA typing of a muscle biopsied sample with 2 months postmortem by comparison with the genotype of the relative. The DNA profile showed common alleles with that of the relative but only 12 from 20 alleles (60%) were identifiable. Then, we performed mt DNA sequencing of the hypervariable region I (HV I) and obtained 100 per cent homology with that of the relative. In conclusion, personal identification can be performed precisely by the data of DNA profile and mtDNA typing compared to the genotype of the relative.

Base Sequence↗
PubMed2000

Paternity testing by PCR-based STR analysis.

We present application of polymerase chain reaction (PCR)-based short tandem repeat (STR) system for use in paternity testing. The process involves a single tube multiplex PCR of 9 STR loci on different chromosomes, in conjunction with Amelogenin sex test and internal size standards, followed by using an automated DNA sequencer to detect amplified products. The results showed that this system provided unambiguously reliable results. In addition, the method is useful for routine use in that it is robust and reproducible and provides a reliable means of paternity testing.

Humans↗
PubMed2000

Comparison of DNA extraction from blood stain and decomposed muscle in STR polymorphism analysis.

Forensic samples that are often degraded and limited in quality cause DNA typing analysis by conventional methods unsuitable. We performed a single tube-multiplex PCR on 9 STR loci (D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, and D7S820) and the X-Y homologous gene amelogenin of DNA extracted from six week postmortem blood stain and decomposed muscle by using QIAGEN QIAamp blood or tissue procedure. An automated genetic analyzer based on fluorescent dye technology was used to detect STR allele patterns. The DNA profile of blood stain sample obtained a complete and unambiguous pattern, whereas, that of muscle DNA extracted from QIAamp tissue and Chelex plus QIAamp blood protocols showed detected STR alleles for 70 per cent and 50 per cent of all tested alleles, respectively. The degraded muscle DNA could not yield amplified products of large size STR alleles; CSF1PO, D13S317 and D7S820. However, the analysis which relied upon the PCR-based STR polymorphism analysis and automated genetic analyzer system offers an ideal strategy for forensic identification.

Autopsy↗
PubMed2000

p53 status and human papillomavirus infection in Thai women with cervical carcinoma.

Loss of p53 function has been implicated in a wide variety of human malignacies. Many studies suggest that in cervical carcinoma p53 function is inactivated either by gene mutation or by complex formation with E6 oncoprotein product of high-risk human papillomavirus (HPV). The aim of this study was to determine the status of HPV infection and p53 gene mutation as well as their correlation in cervical carcinomas. Formalin-fixed paraffin-embedded tissues of 12 cervicitis, 21 cervical intraepithelial neoplasia grade 3 (CIN 3) and 17 squamous cell carcinomas were determined for the presence of HPV using polymerase chain reaction (PCR) amplification and dot blot hybridization. The status of p53 mutations in exons 5-8 was evaluated by polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) and confirmed by direct nucleotide sequencing. HPV infections were detected in all CIN 3 and squamous cell carcinomas (100%). Mutations of p53 were present in 3 of 38 HPV-positive samples: one with an ATG-->TTG transversion (Met-->Leu) in codon 237 of exon 7; and the others with a TGC-->TGG transversion (Cys-->Trp) in codon 242 of exon 7, and a CGT-->CCT transversion (Arg-->Pro) in codon 273 of exon 8, respectively. Our findings show that the frequency of p53 mutation is low in primary cervical carcinoma and that the p53 gene mutation and HPV infection are not mutually exclusive events in the development of cervical cancer. Thus, other genetic events independent of p53 inactivation may also significantly contribute to the carcinogenesis of the uterine cervix.

Carcinoma, Squamous Cell↗
PubMed1999

Maternal viral load and vertical transmission of HIV-1 in mid-trimester gestation.

BACKGROUND: It is now accepted that the majority of HIV-1 vertical transmissions occur in late gestation and at the time of delivery. However, there is wide variation in the prevalence rate of mid-trimester vertical transmission. We assessed the maternal HIV-1 RNA viral load and in utero transmission during mid-trimester gestation. METHODS: Patients were enrolled when they decided to have their pregnancies terminated between 17 and 24 weeks of gestation. Prostaglandin-induced abortion with PGE1 analogue vaginal administration was carried out in all patients. Maternal plasma HIV-1 RNA viral load and plasma HIV-1 RNA (qualitative) from abortus heart blood were assessed. RESULTS: Amongst 41 HIV-1 seropositive pregnant women not receiving antiretroviral therapy plasma HIV-1 RNA was detected in the abortus heart blood from two women (4.9%; 95% confidence interval (CI), 0.6-16.5). Transmission occurred in one out of nine (11.1%; 95% CI, 0.3-48.2) with maternal viral load > or =100000 copies/ml versus one out of 32 (3.1%; 95% CI, 0.1-16.2) of those with <100000 copies/ml (P = 0.39). CONCLUSIONS: The frequency of HIV-1 vertical transmission during mid-trimester was approximately 5% as detected by plasma HIV-1 RNA (qualitative) method in the fetuses aborted from the prostaglandin termination of pregnancy. During mid-trimester gestation there was no correlation between high maternal viral load and vertical transmission.

Adult↗
PubMed1994

Detection of herpes simplex virus type 2 Bgl II N fragment in paraffin-embedded cervical tissue sections using nested polymerase chain reaction.

To study the presence of transforming sequence Bgl II N of HSV-2 in cervical cancer tissues, we developed the nested polymerase chain reaction (PCR) for detecting such a sequence in paraffin-embedded cervical tissue sections. Samples derived from 46 patients with premalignant and malignant lesions were tested. The sequence was found in 20-25% of total cases tested but not observed in any of the normal healthy controls. This study also indicates that for the detection of HSV-2 Bgl II N sequence in cervical tissue, the nested PCR may be more reliable than the in situ hybridization method.

Adenocarcinoma↗
PubMed1994

Detection of various types of human papillomaviruses in premalignant and malignant cervical lesions using DNA-DNA in situ hybridization.

Detection of human papillomavirus (HPV) in formalin-fixed paraffin embedded tissue sections by in situ hybridization technique employing biotinylated (HPV) DNA probe 6/11, 16/18 and 31/33/35 was done retrospectively in 25 cases of cervical dysplasia, 32 cases of cervical squamous cell carcinoma in situ, 52 cases of invasive cervical squamous cell carcinoma and 7 cases of adenocarcinoma. HPV could be demonstrated in 10 cases (40.00%) of cervical dysplasia, 8 cases (25.00%) of cervical squamous cell carcinoma in situ and 31 cases (59.61%) of invasive cervical squamous cell carcinoma and 4 cases (57.14%) of adenocarcinoma. Among the dysplastic cases, 4 cases showed HPV 31/33/35, 4 cases showed HPV 16/18 together with HPV 31/33/35, 1 case showed mixed typing of HPV 6/11 and 31/33/35, and 1 case showed mixed typing of HPV 6/11, 16/18 and 31/33/35. In 32 cases of squamous cell carcinoma in situ, 1 case of HPV 6/11; 3 cases of HPV 16/18, 3 cases of HPV 31/33/35 and 1 case of mixed typing of HPV 16/18 and 31/33/35 were present. A case of HPV 6/11, 10 cases of HPV 16/18 and 9 cases of HPV 31/33/35 could be detected among the cases of invasive squamous cell carcinoma. Mixed typing of HPV 6/11 and 16/18; HPV 6/11 and 31/33/35; HPV 16/18 and 31/33/35; HPV 6/11, 16/18 and 31/33/35 were revealed in 2, 1, 3 and 5 cases of invasive squamous cell carcinoma, respectively. In 7 cases of adenocarcinoma, 1, 2 and 1 cases exhibited positivity for HPV 16/18; HPV 6/11 and HPV 16/18; and HPV 16/18 and HPV 31/33/35.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA Probes, HPV↗
PubMed1989

Rapid detection of herpes simplex virus DNA by in situ hybridization with photobiotin-labelled double-stranded DNA probes.

An assay for rapid detection of herpes simplex virus in infected cells is described. The assay utilizes in situ hybridization with photobiotin-labelled double-stranded DNA probes prepared from HSV-1 DNA cloned in plasmid vectors. The assay provided an alternative method for earlier detection of virus in cell cultures with the ease of preparation of photobiotin-labelled double-stranded DNA.

Animals↗
PubMed1989

Recovery frequencies of herpes simplex virus types 1 and 2 from symptomatic and asymptomatic genital herpes cases and antiviral sensitivities of isolates.

Herpes simplex viruses were isolated from 40.8 to 56.0 per cent of the patients with genital herpes. The frequency of recovery seemed to be higher in females than in males, particularly during the first episode of infection. Asymptomatic shedding of the virus from female genitalias was approximately 0.7 per cent. Herpes simplex virus type 2 represented 98.4 per cent of all isolates and the remaining isolates were type 1. These isolates exhibited a wide range of sensitiveness to 9-(2-hydroxyethoxymethyl) guanine (acyclovir) as demonstrated by antiviral inhibition assay and no single strain exhibited high in vitro drug ID50 value.

Female↗
PubMed1987

Evaluation of biotin-streptavidin enzyme-linked immunosorbent assay for detection of genital herpes simplex virus infection.

A biotin-streptavidin enzyme-linked immunosorbent assay (B-SA ELISA) was evaluated for detection of herpes simplex virus (HSV) in clinical specimens which were cervico-vaginal swabs from 205 asymptomatic women and swabs from the genital lesions of 163 suspected patients. All specimens were also subjected to a conventional virus isolation in cell culture. A blocking B-SA ELISA had 100% specificity and 98% sensitivity compared with viral isolation from patients, but had only 40% sensitivity using specimens from asymptomatics. The conventional B-SA ELISA might also be used; it gave results corresponding to B-SA ELISA blocking test except for a single specimen which was considered a false positive.

Antigens, Viral↗
PubMed1982

Use of in vivo infected spleen cells to study Fv-2r-mediated resistance of mice to Friend spleen focus-forming virus.

In vivo infection of DBA/2 and D2.Fv-2r mice with 10(5) FFU of FV resulted in a rapid adsorption of virus onto the spleen cells. Thus, these cells could be used in the analysis of Fv-2 expression on FV target cells without any difficulty in avoiding extracellular FV particles. Higher frequencies of cells capable of forming IC could be detected in the spleen than in the bone marrow at 2 and 48 h post infection and levels were very low in D2.Fv-2r mice. When recently infected cells were transferred to secondary Fv-2s recipients shortly after infection had been established, the virus-replicating cells released SFFV equally well regardless of whether they originated from Fv-2s or Fv-2r mice. This suggests that suppression of SFFV replication may not take place in Fv-2r cells at an early stage of infection.

Animals↗
PubMedDate not supplied

Restriction endonuclease analysis of deoxyribonucleic acid (DNA) from genital herpes simplex virus type 2 isolates in Thailand.

Local herpes simplex virus (HSV) isolates were characterized by the use of BamHI, KpnI, and EcoRI restriction endonucleases. Analysis of 120 clinical isolates by observation of presence or absence of cleavage sites and of mobility variation in deoxyribonucleic acid (DNA) fragments from the terminal and joint regions of the HSV genome revealed that 112 (93.3%) were type-2 (HSV-2) and the others were type-1 (HSV-1), mixed HSV-2 and HSV-1, and mixed HSV-2 strains. The genomes of HSV-2 isolates were highly conserved and could be classified into 25 distinct restriction endonuclease (RE) cleavage patterns, which differed from those obtained with isolates of other countries.

DNA Restriction Enzymes↗